Hip replacement surgery has been called the operation of the century by “The Lancet” medical journal. Certainly, most would agree that hip and knee replacement has dramatically changed the lives of millions of people over the last several decades. Striking a balance between innovation and patient safety is always the challenge of any industry. Innovation has led to changes in fixation of hip replacements from all-cemented total joint replacements in the 1970s and early 1980s to primarily cementless hip replacements currently. These changes were not without some misadventures, but ultimately a more durable form of fixation that gives the opportunity for long-term successful outcome has evolved. We have seen significant changes in bearing surfaces over the last 2 decades. The traditional metal on conventional polyethylene has evolved to metal on cross-linked polyethylene, ceramic on ceramic, ceramic on cross-linked polyethylene. There are still advocates of metal-on-metal bearings, and in fact, many with that bearing combination continue to do extremely well. Some advocate waiting for long-term followup before implants are released for general use. On the one hand, this would avoid unintended consequences for a population of patients, but on the other hand, it would artificially withhold innovative products from improving the lives of patients. I think a balance needs to be struck between evaluating new technology and artificially withholding new technology from the patient population. By listening to all stake-holders in this formula, including patients, physicians actually using the device or drug, and manufacturers, we can hopefully “get it right” when it comes to innovation in new technology.

In a recent article in the Journal of the American Academy of Orthopedic Surgeons September, 2014 the authors Bryan Bobat, M.D. et al discussed decades of research looking at the aging process and the influence of improved fitness on that aging process. It has been well-documented that individuals participating in high levels of physical activity have better bone density, lower risk of fracture, increased muscle mass and more flexibility in their tendons and ligaments. It has also been shown that exercise will lead to improved volume or thickness of cartilage covering the ends of our bones. The authors recommended that a combination of physical fitness be utilized by aging individuals. This includes resistance training or weight lifting, endurance training or some type of cardiac fitness such as running, fast walking, biking and Stairmaster, etcetera. In addition to weight training and endurance training, flexibility and balance exercises are important to enhance function. The combination of increasing physical activity and managing weight is critically important to older adults because they are the fastest growing and least active age group in the United States. It has been well documented that age related deterioration of muscle and strength, and secondary chronic medical problems, can be improved by participation in a program to increase activity. It has also been document that people who are physically fit exhibit lower rates of anxiety and depression compared to sedentary individuals. In summary, improving our activity level and improving our physical fitness will have multiple positive benefits on our overall health.

We recently reviewed our data from calendar year 2013 looking at our results for primary total hip and knee replacement. In an effort to be transparent with regard to expectations, we track our average length of stay, infection, readmission rate within 30 days and look at disposition after surgery. This is data that all hospitals keep and the data base is available to compare to benchmark data i.e., what is expected or best practices.

We performed over 1,000 joint replacements in 2013. Our average length of stay for total hip replacement was 2.2 days which compared with a national benchmark of 2.6 days; therefore we were better than expected as far as our length of stay. With knee replacement our average leg of stay was 2.8 days. The benchmark average was 2.6 days. Our discharge to home for both hip and knee replacement was 90%, home with visiting nurse services was 2% and discharge to a skilled nursing facility was 8%; both for our primary hips and knees. This compares quite favorably with the Cleveland Clinic 2012 data which had a discharge home of 62% for hip replacement and 49% for knee replacement. Our infection rate for primary total hips was 0.8% and for primary total knees 0.7%, again both better than the national benchmarking data, where infection rates range from 1% to 1.5%. Our 30 day readmission, that is return to the hospital for any reason after discharge for a primary hip or knee replacement, was 3.3% for hips and 3.4% for knees; both of which are essentially half of what the national benchmarking average is for 30 day readmission.

By collecting and reviewing this data we continually strive to improve the outcomes of our patients. As you can see from our 2013 data our length of stay is equal to or better than the national average, our risk of infection is lower, the risk of readmission to the hospital within 30 days of surgery is essentially half that of the national benchmarking and the probability of being discharged to home is greater than 90%, again significantly better than the national benchmarking data. We feel that through the combination of standardized pathways, preoperative education and preparation, and maximizing the patient’s health and fitness prior to surgery, we are able to obtain data that exceeds national benchmarking data. It is this comprehensive approach to joint replacement that has made the Joint Center at Valley Medical Center #1 in the state of Washington for the last 4 years in a row. For more information visit our website at Valley Medical Center.org.

At the recent Knee Society meeting in New Orleans, Louisiana, from March 15, 2014, there are several papers relating to the question of what is the ideal alignment of a leg after knee replacement. There was no clear consensus on what ideal alignment is other than making sure that the leg is mechanically straight and the soft tissue is well balanced. There are several options for obtaining alignment during a knee replacement. These include conventional instruments, which are based on fixed points on the thigh bone and shin bone, computer-assisted surgery that uses computers to help with alignment, and patient-specific guides which are developed from preoperative CT scans or MRIs of the patient’s lower extremity and then custom or one-time use cutting guides are made for that particular surgical procedure. All of these options have enjoyed success, and there is no clearcut winner based on literature data from 2014. The custom cutting guides as well as computer-assisted surgery increase the cost and time associated with the replacement procedure. Studies will continue to help elucidate whether or not one form of alignment is more reliable for use in knee replacement surgery.

In a paper presented at the Knee Society Meeting in New Orleans, Louisiana 03/15/2014, Dr. Javad Parvizi presented results of their work on preventing joint infection after total joint replacement. They found strong evidence to support preoperative health and nutritional status optimization, the use of prophylactic IV antibiotics, antibiotic impregnated cement, and preoperative skin preparation prior to surgery.

This supports the program that we instituted atValley Medical Center, which includes preoperative skin decolonization, use of chlorhexidine preparation of the skin prior to surgery and in the operating room itself, nasal decolonization with diluted iodine solution, and vigilant follow up of patients to minimize the risk of infection. There are multi-modal approaches to minimizing risk of infection that begin with optimization of the patient prior to surgery and extending through the preoperative and postoperative period.

Dr. Browne and Associates presented an award winning paper at the Knee Society Meeting in New Orleans, Louisiana 03/15/2014 looking at the effect of morbid obesity on complications after knee replacement. They used a nation wide inpatient sample database to identify patients undergoing primary knee replacement from October 2005 to December 2008. Morbid obesity was defined as a Body Mass Index over 40. Of the 1,777,068 primary total knees 98,410 or 5.5% of patients were categorized as morbidly obese. These individuals had a statistically higher risk of postoperative in-hospital wound complications including infection, and higher risk for anemia and renal complications. They also noted that morbidly obese patients were at a significantly higher risk of in-hospital death following total knee replacement compared to non-obese patients. They concluded that morbid obesity by itself appears to be associated with a higher risk for complications following total knee replacement. They also noted that comorbidities that are often associated with obesity including diabetes and hypertension appear to be responsible for some of the increased risks of complication following surgery. They also noted that morbid obesity appears to be associated with higher costs, longer length of stay, and a lower rate of discharge home after knee replacement surgery.

The American Academy of Orthopedic Surgeons had their annual meeting in New Orleans, Louisiana March 11th through the 16th. On March 15th, the hip society had their annual open meeting and there were several papers focused on preventing readmission to the hospital after joint replacement. There is emerging information particularly when looking at Medicare claims data, which allows the analysis of tens of thousands of patients. The focus of these papers was how to prevent readmission following surgery. Readmission often involves several causes. The most common being some type of cardiac event related to either coronary artery disease or irregular heart rates. Another source of readmission is infection as well as blood clots in the lower extremities. Several authors noted that there are many modifiable risk factors that if addressed prior to a surgery can avoid complications and readmission to the hospital. Looking at the most common risk factors associated with patients undergoing joint replacement they are in order or prevalence: Hypertension, elevated cholesterol, diabetes, depression, morbid obesity, and heart disease. Having appropriate preoperative evaluation by a patient’s internist or a hospital associated internal medicine group can help identify and hopefully treat many of these modifiable risk factors. High blood pressure can be controlled with medication as can elevated cholesterol. Diabetes can be appropriately managed so that the patient metabolically is as stable as possible prior to surgery. Obesity has gotten quite a bit of exposure over the last year to add the importance of losing weight to decrease the risk of infection and other complications after hip replacement. Most large volume centers are starting or have clinics in place to help patients with modifiable risk factors prior to surgery. Patients should look into these prior to considering joint replacement surgery.

At the most recent Knee Society meeting in New Orleans, Louisiana, March 15, 2014, there were several papers published revealing the percentage of patients who were happy or satisfied after receiving a knee replacement. As was noted by Michael Dunbar, MD, patient satisfaction encompassed many intrinsic and extrinsic factors related to the patient’s experience.

The Swedish Knee Arthroplasty registry, which is a large population study, noted that 17% of patients who had a knee replacement were dissatisfied with some aspect of their knee replacement outcome. Several other large registries have noted a similar rate of patient dissatisfaction. All of these studies indicate the satisfaction after knee replacement correlates most strongly with pain relief, followed by improvement of function. Satisfaction is noted to be a function of the duration of the disease process leading to the knee replacement with patients who have a longstanding history of arthritic problems reporting higher rates of satisfaction compared to those with more acute onset of knee problems.

Unmet expectations are a significant factor associated with dissatisfaction after knee replacement.

The authors pointed out that it is important for the patient and their care team to have a discussion about what is and what is not to be expected after knee replacement and to have a discussion about the anticipated pain relief in function and activity after knee replacement surgery.

At the 23rd annual meeting of the American Association of Hip and Knee Surgeons in Dallas, Texas, November 8 through 10, 2013, a paper was presented by Dr. Hamula, Et Al, evaluating the use of patient-specific cutting guides for total knee replacement. Their study demonstrated use of these guides was not superior to standard instrumentation with regard to alignment of the knee replacement. There was an increased cost associated with these guides associated with the preop MRI or CT scan that was required as well as the additional expense of the cutting guide.

This study comes to a similar conclusion as one that I recently had accepted in “The Journal of Arthroplasty” in 2013. We found that use of patient-specific cutting guides yielded similar results to conventional instrumentation as well as computer-assisted instrumentation. There is some additional cost, which is partially offset by the increased efficiency of the procedure.

We currently use these guides in patients who have specific deformities that preclude the use of conventional instrumentation. In that setting, they are extremely useful for improving accuracy of the knee replacement. While widespread use for routine cases may not be justified, use of these guides is extremely helpful in specific situations.

At the 23rd annual meeting of the American Association of Hip and Knee Surgeons in Dallas, Texas, November 8 through 10, 2013, Doctors Lang, Et Al, reviewed a large retrospective database using a Nationwide Inpatient Sample (NIS). They found that the total number of hip replacements increased by 73% in the decade from 2000 to 2009, but breaking that down, it increased by 123% in patients age 45 to 64, and by 54% in patients 65 to 84. This reflects the growing demand for hip replacement in a younger age group who are limited by osteoarthritis. This trend makes it incumbent upon orthopedic surgeons and orthopedic implant manufacturers to try to improve results and longevity as patients can anticipate having implants in their body for a longer period of time.